Optical imaging lens

ABSTRACT

An optical imaging lens includes a first lens element to an eighth lens element. The first lens element has positive refracting power, a periphery region of the image-side surface of the first lens element is concave, a periphery region of the object-side surface of the third lens element is concave, an optical axis region of the image-side surface of the sixth lens element is convex, an optical axis region of the object-side surface of the eighth lens element is convex, and a periphery region of the image-side surface of the eighth lens element is convex. Lens elements included by the optical imaging lens are only eight lens elements described above to satisfy D41t51/(T3+G34)≥1.700.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to an optical imaging lens.Specifically speaking, the present invention is directed to an opticalimaging lens for using in a portable electronic device such as a mobilephone, a camera, a tablet personal computer, a personal digitalassistant (PDA), or a head-mounted display (AR, VR, MR) for takingpictures or for recording videos.

2. Description of the Prior Art

The specifications of portable electronic devices are changing with eachpassing day, and its key component: the optical imaging lens is alsodeveloping more diversified. The main lens element of portableelectronic devices not only requires a larger f-number and maintains ashorter system length, but also pursues higher pixels and higherresolution. High pixels imply that the image height of the opticalimaging lens must be increased, and larger image sensors are used toreceive imaging rays to increase the pixel demand. However, the designof large aperture allows the optical imaging lens to receive moreimaging rays, which makes the design more difficult. The high pixelsmake the resolution of the optical imaging lens higher, and the largeaperture makes the design more difficult. Therefore, how to add multiplelens elements to the optical imaging lens in the limited system lengthand increase the resolution, the f-number and the image height at thesame time is a problem that needs to be challenged and solved.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide an optical imaging lenshaving eight lens elements with larger aperture, larger image height andhigh resolution.

In an embodiment of the present invention, the first lens element haspositive refracting power, and a periphery region of the image-sidesurface of the first lens element is concave, a periphery region of theobject-side surface of the third lens element is concave, an opticalaxis region of the image-side surface of the sixth lens element isconvex, an optical axis region of the object-side surface of the eighthlens element is convex, and a periphery region of the image-side surfaceof the eighth lens element is convex. Lens elements included by theoptical imaging lens are only the eight lens elements described above,and the optical imaging lens satisfies the relationships:D41t51/(T3+G34)≥1.700.

In another embodiment of the present invention, a periphery region ofthe object-side surface of the third lens element is concave, aperiphery region of the object-side surface of the fourth lens elementis concave, an optical axis region of the image-side surface of thesixth lens element is convex, an optical axis region of the object-sidesurface of the eighth lens element is convex, and a periphery region ofthe image-side surface of the eighth lens element is convex. Lenselements included by the optical imaging lens are only the eight lenselements described above, and the optical imaging lens satisfies therelationships: D41t51/(T3+G34)≥1.700.

In another embodiment of the present invention, the first lens elementhas positive refracting power, and a periphery region of the image-sidesurface of the first lens element is concave, the second lens elementhas negative refracting power, a periphery region of the image-sidesurface of the fourth lens element is convex, an optical axis region ofthe image-side surface of the sixth lens element is convex, an opticalaxis region of the object-side surface of the eighth lens element isconvex, and a periphery region of the image-side surface of the eighthlens element is convex. Lens elements included by the optical imaginglens are only the eight lens elements described above, and the opticalimaging lens satisfies the relationships: D41t61/(T3+G34)≥3.700.

In the optical imaging lens of the present invention, the embodimentsmay also selectively satisfy the following optical relationships:

D11t41/T4≤4.300;

(D42t52+D62t82)/(G56+T6)≤4.100;

EFL/(T1+T6+T8)≤4.000;

TTL/(T1+G56+T6+T8)≤4.000;

Fno*(T1+G12+T3+G34)/(T2+G23)≤3.110;

3.800≤(ImgH+EPD+G56+T6)/D31t52;

V3+V8≤100.000;

V7+V8≤100.000;

Fno*(T2+G34+T4+D62t82)/AAG≤3.600;

6.100≤(ImgH+D41t62)/(G67+T7+G78);

Fno*(ALT+BFL)/D41t62≤4.000;

3.600≤EPD/(G67+T7);

55.000≤V2+V6;

Fno*TTL/EPD≤4.100;

D31t42/T8≤2.700;

(D11t41+D41t62)/D62t82≤5.400; and

3.000≤(EPD+EFL)/D11t41.

In the present invention, T1 is a thickness of the first lens elementalong the optical axis, T2 is a thickness of the second lens elementalong the optical axis, T3 is a thickness of the third lens elementalong the optical axis, T4 is a thickness of the fourth lens elementalong the optical axis, T6 is a thickness of the sixth lens elementalong the optical axis, T7 is a thickness of the seventh lens elementalong the optical axis, T8 is a thickness of the eighth lens elementalong the optical axis, G12 is an air gap between the first lens elementand the second lens element along the optical axis, G23 is an air gapbetween the second lens element and the third lens element along theoptical axis, G34 is an air gap between the third lens element and thefourth lens element along the optical axis, G56 is an air gap betweenthe fifth lens element and the sixth lens element along the opticalaxis, G67 is an air gap between the sixth lens element and the seventhlens element along the optical axis, G78 is an air gap between theseventh lens element and the eighth lens element along the optical axis,ALT is a sum of thicknesses of the eight lens elements from the firstlens element to the eighth lens element along the optical axis, TTL isthe distance from the object-side surface of the first lens element toan image plane along the optical axis, BFL is a distance from theimage-side surface of the eighth lens element to the image plane alongthe optical axis, AAG is a sum of seven air gaps from the first lenselement to the eighth lens element along the optical axis, EFL is aneffective focal length of the optical imaging lens, ImgH is an imageheight of the optical imaging lens, Fno is a f-number of the opticalimaging lens, EPD is an entrance pupil diameter of the optical imaginglens, V2 is an Abbe number of the second lens element; V3 is an Abbenumber of the third lens element; V6 is an Abbe number of the sixth lenselement; V7 is an Abbe number of the seventh lens element; and V8 is anAbbe number of the eighth lens element.

In addition, D41t51 is defined as the distance from the object-sidesurface of the fourth lens element to the object-side surface of thefifth lens element along the optical axis, D41t61 is defined as thedistance from the object-side surface of the fourth lens element to theobject-side surface of the sixth lens element along the optical axis,D11t41 is defined as the distance from the object-side surface of thefirst lens element to the object-side surface of the fourth lens elementalong the optical axis, D42t52 is defined as the distance from theimage-side surface of the fourth lens element to the image-side surfaceof the fifth lens element along the optical axis, D62t82 is defined asthe distance from the image-side surface of the sixth lens element tothe image-side surface of the eighth lens element along the opticalaxis, D31t52 is defined as the distance from the object-side surface ofthe third lens element to the image-side surface of the fifth lenselement along the optical axis, D41t62 is defined as the distance fromthe object-side surface of the fourth lens element to the image-sidesurface of the sixth lens element along the optical axis, D31t42 isdefined as the distance from the object-side surface of the third lenselement to the image-side surface of the fourth lens element along theoptical axis.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-5 illustrate the methods for determining the surface shapes andfor determining optical axis region or periphery region of one lenselement.

FIG. 6 illustrates a first embodiment of the optical imaging lens of thepresent invention.

FIG. 7A illustrates the longitudinal spherical aberration on the imageplane of the first embodiment.

FIG. 7B illustrates the field curvature aberration on the sagittaldirection of the first embodiment.

FIG. 7C illustrates the field curvature aberration on the tangentialdirection of the first embodiment.

FIG. 7D illustrates the distortion of the first embodiment.

FIG. 8 illustrates a second embodiment of the optical imaging lens ofthe present invention.

FIG. 9A illustrates the longitudinal spherical aberration on the imageplane of the second embodiment.

FIG. 9B illustrates the field curvature aberration on the sagittaldirection of the second embodiment.

FIG. 9C illustrates the field curvature aberration on the tangentialdirection of the second embodiment.

FIG. 9D illustrates the distortion of the second embodiment.

FIG. 10 illustrates a third embodiment of the optical imaging lens ofthe present invention.

FIG. 11A illustrates the longitudinal spherical aberration on the imageplane of the third embodiment.

FIG. 11B illustrates the field curvature aberration on the sagittaldirection of the third embodiment.

FIG. 11C illustrates the field curvature aberration on the tangentialdirection of the third embodiment.

FIG. 11D illustrates the distortion of the third embodiment.

FIG. 12 illustrates a fourth embodiment of the optical imaging lens ofthe present invention.

FIG. 13A illustrates the longitudinal spherical aberration on the imageplane of the fourth embodiment.

FIG. 13B illustrates the field curvature aberration on the sagittaldirection of the fourth embodiment.

FIG. 13C illustrates the field curvature aberration on the tangentialdirection of the fourth embodiment.

FIG. 13D illustrates the distortion of the fourth embodiment.

FIG. 14 illustrates a fifth embodiment of the optical imaging lens ofthe present invention.

FIG. 15A illustrates the longitudinal spherical aberration on the imageplane of the fifth embodiment.

FIG. 15B illustrates the field curvature aberration on the sagittaldirection of the fifth embodiment.

FIG. 15C illustrates the field curvature aberration on the tangentialdirection of the fifth embodiment.

FIG. 15D illustrates the distortion of the fifth embodiment.

FIG. 16 illustrates a sixth embodiment of the optical imaging lens ofthe present invention.

FIG. 17A illustrates the longitudinal spherical aberration on the imageplane of the sixth embodiment.

FIG. 17B illustrates the field curvature aberration on the sagittaldirection of the sixth embodiment.

FIG. 17C illustrates the field curvature aberration on the tangentialdirection of the sixth embodiment.

FIG. 17D illustrates the distortion of the sixth embodiment.

FIG. 18 illustrates a seventh embodiment of the optical imaging lens ofthe present invention.

FIG. 19A illustrates the longitudinal spherical aberration on the imageplane of the seventh embodiment.

FIG. 19B illustrates the field curvature aberration on the sagittaldirection of the seventh embodiment.

FIG. 19C illustrates the field curvature aberration on the tangentialdirection of the seventh embodiment.

FIG. 19D illustrates the distortion of the seventh embodiment.

FIG. 20 shows the optical data of the first embodiment of the opticalimaging lens.

FIG. 21 shows the aspheric surface data of the first embodiment.

FIG. 22 shows the optical data of the second embodiment of the opticalimaging lens.

FIG. 23 shows the aspheric surface data of the second embodiment.

FIG. 24 shows the optical data of the third embodiment of the opticalimaging lens.

FIG. 25 shows the aspheric surface data of the third embodiment.

FIG. 26 shows the optical data of the fourth embodiment of the opticalimaging lens.

FIG. 27 shows the aspheric surface data of the fourth embodiment.

FIG. 28 shows the optical data of the fifth embodiment of the opticalimaging lens.

FIG. 29 shows the aspheric surface data of the fifth embodiment.

FIG. 30 shows the optical data of the sixth embodiment of the opticalimaging lens.

FIG. 31 shows the aspheric surface data of the sixth embodiment.

FIG. 32 shows the optical data of the seventh embodiment of the opticalimaging lens.

FIG. 33 shows the aspheric surface data of the seventh embodiment.

FIG. 34 shows some important ratios in the embodiments.

FIG. 35 shows some important ratios in the embodiments.

DETAILED DESCRIPTION

The terms “optical axis region”, “periphery region”, “concave”, and“convex” used in this specification and claims should be interpretedbased on the definition listed in the specification by the principle oflexicographer.

In the present disclosure, the optical system may comprise at least onelens element to receive imaging rays that are incident on the opticalsystem over a set of angles ranging from parallel to an optical axis toa half field of view (HFOV) angle with respect to the optical axis. Theimaging rays pass through the optical system to produce an image on animage plane. The term “a lens element having positive refracting power(or negative refracting power)” means that the paraxial refracting powerof the lens element in Gaussian optics is positive (or negative). Theterm “an object-side (or image-side) surface of a lens element” refersto a specific region of that surface of the lens element at whichimaging rays can pass through that specific region. Imaging rays includeat least two types of rays: a chief ray Lc and a marginal ray Lm (asshown in FIG. 1 ). An object-side (or image-side) surface of a lenselement can be characterized as having several regions, including anoptical axis region, a periphery region, and, in some cases, one or moreintermediate regions, as discussed more fully below.

FIG. 1 is a radial cross-sectional view of a lens element 100. Tworeferential points for the surfaces of the lens element 100 can bedefined: a central point, and a transition point. The central point of asurface of a lens element is a point of intersection of that surface andthe optical axis I. As illustrated in FIG. 1 , a first central point CP1may be present on the object-side surface 110 of lens element 100 and asecond central point CP2 may be present on the image-side surface 120 ofthe lens element 100. The transition point is a point on a surface of alens element, at which the line tangent to that point is perpendicularto the optical axis I. The optical boundary OB of a surface of the lenselement is defined as a point at which the radially outermost marginalray Lm passing through the surface of the lens element intersects thesurface of the lens element. All transition points lie between theoptical axis I and the optical boundary OB of the surface of the lenselement. A surface of the lens element 100 may have no transition pointor have at least one transition point. If multiple transition points arepresent on a single surface, then these transition points aresequentially named along the radial direction of the surface withreference numerals starting from the first transition point. Forexample, the first transition point, e.g., TP1, (closest to the opticalaxis I), the second transition point, e.g., TP2, (as shown in FIG. 4 ),and the Nth transition point (farthest from the optical axis I).

When a surface of the lens element has at least one transition point,the region of the surface of the lens element from the central point tothe first transition point TP1 is defined as the optical axis region,which includes the central point. The region located radially outside ofthe farthest transition point (the Nth transition point) from theoptical axis I to the optical boundary OB of the surface of the lenselement is defined as the periphery region. In some embodiments, theremay be intermediate regions present between the optical axis region andthe periphery region, with the number of intermediate regions dependingon the number of the transition points. When a surface of the lenselement has no transition point, the optical axis region is defined as aregion of 0%-50% of the distance between the optical axis I and theoptical boundary OB of the surface of the lens element, and theperiphery region is defined as a region of 50%-100% of the distancebetween the optical axis I and the optical boundary OB of the surface ofthe lens element.

The shape of a region is convex if a collimated ray being parallel tothe optical axis I and passing through the region is bent toward theoptical axis I such that the ray intersects the optical axis I on theimage side A2 of the lens element. The shape of a region is concave ifthe extension line of a collimated ray being parallel to the opticalaxis I and passing through the region intersects the optical axis I onthe object side A1 of the lens element.

Additionally, referring to FIG. 1 , the lens element 100 may also have amounting portion 130 extending radially outward from the opticalboundary OB. The mounting portion 130 is typically used to physicallysecure the lens element to a corresponding element of the optical system(not shown). Imaging rays do not reach the mounting portion 130. Thestructure and shape of the mounting portion 130 are only examples toexplain the technologies, and should not be taken as limiting the scopeof the present disclosure. The mounting portion 130 of the lens elementsdiscussed below may be partially or completely omitted in the followingdrawings.

Referring to FIG. 2 , optical axis region Z1 is defined between centralpoint CP and first transition point TP1. Periphery region Z2 is definedbetween TP1 and the optical boundary OB of the surface of the lenselement. Collimated ray 211 intersects the optical axis I on the imageside A2 of lens element 200 after passing through optical axis regionZ1, i.e., the focal point of collimated ray 211 after passing throughoptical axis region Z1 is on the image side A2 of the lens element 200at point R in FIG. 2 . Accordingly, since the ray itself intersects theoptical axis I on the image side A2 of the lens element 200, opticalaxis region Z1 is convex. On the contrary, collimated ray 212 divergesafter passing through periphery region Z2. The extension line EL ofcollimated ray 212 after passing through periphery region Z2 intersectsthe optical axis I on the object side A1 of lens element 200, i.e., thefocal point of collimated ray 212 after passing through periphery regionZ2 is on the object side A1 at point M in FIG. 2 . Accordingly, sincethe extension line EL of the ray intersects the optical axis I on theobject side A1 of the lens element 200, periphery region Z2 is concave.In the lens element 200 illustrated in FIG. 2 , the first transitionpoint TP1 is the border of the optical axis region and the peripheryregion, i.e., TP1 is the point at which the shape changes from convex toconcave.

Alternatively, there is another way for a person having ordinary skillin the art to determine whether an optical axis region is convex orconcave by referring to the sign of “Radius of curvature” (the “R”value), which is the paraxial radius of shape of a lens surface in theoptical axis region. The R value is commonly used in conventionaloptical design software such as Zemax and CodeV. The R value usuallyappears in the lens data sheet in the software. For an object-sidesurface, a positive R value defines that the optical axis region of theobject-side surface is convex, and a negative R value defines that theoptical axis region of the object-side surface is concave. Conversely,for an image-side surface, a positive R value defines that the opticalaxis region of the image-side surface is concave, and a negative R valuedefines that the optical axis region of the image-side surface isconvex. The result found by using this method should be consistent withthe method utilizing intersection of the optical axis by rays/extensionlines mentioned above, which determines surface shape by referring towhether the focal point of a collimated ray being parallel to theoptical axis I is on the object-side or the image-side of a lenselement. As used herein, the terms “a shape of a region is convex(concave),” “a region is convex (concave),” and “a convex-(concave-)region,” can be used alternatively.

FIG. 3 , FIG. 4 and FIG. 5 illustrate examples of determining the shapeof lens element regions and the boundaries of regions under variouscircumstances, including the optical axis region, the periphery region,and intermediate regions as set forth in the present specification.

FIG. 3 is a radial cross-sectional view of a lens element 300. Asillustrated in FIG. 3 , only one transition point TP1 appears within theoptical boundary OB of the image-side surface 320 of the lens element300. Optical axis region Z1 and periphery region Z2 of the image-sidesurface 320 of lens element 300 are illustrated. The R value of theimage-side surface 320 is positive (i.e., R>0). Accordingly, the opticalaxis region Z1 is concave.

In general, the shape of each region demarcated by the transition pointwill have an opposite shape to the shape of the adjacent region(s).Accordingly, the transition point will define a transition in shape,changing from concave to convex at the transition point or changing fromconvex to concave. In FIG. 3 , since the shape of the optical axisregion Z1 is concave, the shape of the periphery region Z2 will beconvex as the shape changes at the transition point TP1.

FIG. 4 is a radial cross-sectional view of a lens element 400. Referringto FIG. 4 , a first transition point TP1 and a second transition pointTP2 are present on the object-side surface 410 of lens element 400. Theoptical axis region Z1 of the object-side surface 410 is defined betweenthe optical axis I and the first transition point TP1. The R value ofthe object-side surface 410 is positive (i.e., R>0). Accordingly, theoptical axis region Z1 is convex.

The periphery region Z2 of the object-side surface 410, which is alsoconvex, is defined between the second transition point TP2 and theoptical boundary OB of the object-side surface 410 of the lens element400. Further, intermediate region Z3 of the object-side surface 410,which is concave, is defined between the first transition point TP1 andthe second transition point TP2. Referring once again to FIG. 4 , theobject-side surface 410 includes an optical axis region Z1 locatedbetween the optical axis I and the first transition point TP1, anintermediate region Z3 located between the first transition point TP1and the second transition point TP2, and a periphery region Z2 locatedbetween the second transition point TP2 and the optical boundary OB ofthe object-side surface 410. Since the shape of the optical axis regionZ1 is designed to be convex, the shape of the intermediate region Z3 isconcave as the shape of the intermediate region Z3 changes at the firsttransition point TP1, and the shape of the periphery region Z2 is convexas the shape of the periphery region Z2 changes at the second transitionpoint TP2.

FIG. 5 is a radial cross-sectional view of a lens element 500. Lenselement 500 has no transition point on the object-side surface 510 ofthe lens element 500. For a surface of a lens element with no transitionpoint, for example, the object-side surface 510 the lens element 500,the optical axis region Z1 is defined as the region of 0%-50% of thedistance between the optical axis I and the optical boundary OB of thesurface of the lens element and the periphery region is defined as theregion of 50%-100% of the distance between the optical axis I and theoptical boundary OB of the surface of the lens element. Referring tolens element 500 illustrated in FIG. 5 , the optical axis region Z1 ofthe object-side surface 510 is defined between the optical axis I and50% of the distance between the optical axis I and the optical boundaryOB. The R value of the object-side surface 510 is positive (i.e., R>0).Accordingly, the optical axis region Z1 is convex. For the object-sidesurface 510 of the lens element 500, because there is no transitionpoint, the periphery region Z2 of the object-side surface 510 is alsoconvex. It should be noted that lens element 500 may have a mountingportion (not shown) extending radially outward from the periphery regionZ2.

As shown in FIG. 6 , the optical imaging lens 1 of eight lens elementsof the present invention, sequentially located from an object side A1(where an object is located) to an image side A2 along an optical axisI, has an aperture stop (ape. stop) 2, a first lens element 10, a secondlens element 20, a third lens element 30, a fourth lens element 40, afifth lens element 50, a sixth lens element 60, a seventh lens element70, an eighth lens element 80, a filter 3 and an image plane 4.Generally speaking, the first lens element 10, the second lens element20, the third lens element 30, the fourth lens element 40, the fifthlens element 50, the sixth lens element 60, the seventh lens element 70and the eighth lens element 80 may be made of a transparent plasticmaterial but the present invention is not limited to this, and each hasan appropriate refracting power. In the present invention, lens elementshaving refracting power included by the optical imaging lens 1 are onlythe eight lens elements (the first lens element 10, the second lenselement 20, the third lens element 30, the fourth lens element 40, thefifth lens element 50, the sixth lens element 60, the seventh lenselement 70, and the eighth lens element 80) described above. The opticalaxis I is the optical axis of the entire optical imaging lens 1, and theoptical axis of each of the lens elements coincides with the opticalaxis of the optical imaging lens 1.

Furthermore, the optical imaging lens 1 includes an aperture stop (ape.stop) 2 disposed in an appropriate position. In FIG. 6 , the aperturestop 2 is disposed on the side of the first lens element 10 facing theobject side A1. In other words, the first lens element 10 is disposedbetween the aperture stop 2 and the second lens 20 element. When rayemitted or reflected by an object (not shown) which is located at theobject side A1 enters the optical imaging lens 1 of the presentinvention, it forms a clear and sharp image on the image plane 4 at theimage side A2 after passing through the aperture stop 2, the first lenselement 10, the second lens element 20, the third lens element 30, thefourth lens element 40, the fifth lens element 50, the sixth lenselement 60, the seventh lens element 70, the eighth lens element 80 andthe filter 3. In one embodiment of the present invention, the filter 3is placed between the eighth lens element 80 and the image plane 4. Theoptional filter 3 may be a filter of various suitable functions, forexample, the filter 3 may be an infrared cut-off filter (IR cut filter),which is used to prevent infrared rays in the imaging ray from beingtransmitted to the image plane 4 to affect the imaging quality.

Each lens element in the optical imaging lens 1 of the present inventionhas an object-side surface facing toward the object side A1 as well asan image-side surface facing toward the image side A2, and each lenselement also has an optical axis region and a periphery regionrespectively. For example, the first lens element 10 has an object-sidesurface 11 and an image-side surface 12; the second lens element 20 hasan object-side surface 21 and an image-side surface 22; the third lenselement 30 has an object-side surface 31 and an image-side surface 32;the fourth lens element 40 has an object-side surface 41 and animage-side surface 42; the fifth lens element 50 has an object-sidesurface 51 and an image-side surface 52; the sixth lens element 60 hasan object-side surface 61 and an image-side surface 62; the seventh lenselement 70 has an object-side surface 71 and an image-side surface 72;and the eighth lens element 80 has an object-side surface 81 and animage-side surface 82. In addition, each object-side surface andimage-side surface in the optical imaging lens 1 of the presentinvention has an optical axis region and a periphery region.

Each lens element in the optical imaging lens 1 of the present inventionfurther has a thickness T along the optical axis I. For example, thefirst lens element 10 has a first lens element thickness T1, the secondlens element 20 has a second lens element thickness T2, the third lenselement 30 has a third lens element thickness T3, the fourth lenselement 40 has a fourth lens element thickness T4, the fifth lenselement 50 has a fifth lens element thickness T5, the sixth lens element60 has a sixth lens element thickness T6, the seventh lens element 70has a seventh lens element thickness T7, the eighth lens element 80 hasan eighth lens element thickness T8. Therefore, the sum of thethicknesses of eight lens elements from the first lens element 10 to theeighth lens element 80 in the optical imaging lens 1 along the opticalaxis I is ALT=T1+T2+T3+T4+T5+T6+T7+T8.

In addition, between two adjacent lens elements in the optical imaginglens 1 of the present invention there may be an air gap along theoptical axis I. For example, there is an air gap G12 disposed betweenthe first lens element 10 and the second lens element 20, an air gap G23disposed between the second lens element 20 and the third lens element30, an air gap G34 disposed between the third lens element 30 and thefourth lens element 40, an air gap G45 disposed between the fourth lenselement 40 and the fifth lens element 50, an air gap G56 disposedbetween the fifth lens element 50 and the sixth lens element 60, an airgap G67 disposed between the sixth lens element 60 and the seventh lenselement 70 as well as an air gap G78 disposed between the seventh lenselement 70 and the eighth lens element 80. Therefore, the sum of sevenair gaps from the first lens element 10 to the eighth lens element 80along the optical axis I is AAG=G12+G23+G34+G45+G56+G67+G78.

In addition, a distance from the object-side surface 11 of the firstlens element 10 to the image plane 4 along the optical axis I is TTL,namely a system length of the optical imaging lens 1; an effective focallength of the optical imaging lens element is EFL; a distance from theobject-side surface 11 of the first lens element 10 to the image-sidesurface 82 of the eighth lens element 80 along the optical axis I is TL;HFOV stands for the half field of view which is half of the field ofview of the entire optical imaging lens 1; ImgH is an image height ofthe optical imaging lens 1, and Fno is a f-number of the optical imaginglens 1, EPD is an entrance pupil diameter of the optical imaging lens,which is equal to the effective focal length EFL of the optical imaginglens 1 divided by the f-number Fno.

When the filter 3 is placed between the eighth lens element 80 and theimage plane 4, an air gap between the eighth lens element 80 and thefilter 3 along the optical axis I is G8F; a thickness of the filter 3along the optical axis I is TF; an air gap between the filter 3 and theimage plane 4 along the optical axis I is GFP; and a distance from theimage-side surface 82 of the eighth lens element 80 to the image plane 4along the optical axis I is BFL. Therefore, BFL=G8F+TF+GFP.

Furthermore, a focal length of the first lens element 10 is f1; a focallength of the second lens element 20 is f2; a focal length of the thirdlens element 30 is f3; a focal length of the fourth lens element 40 isf4; a focal length of the fifth lens element 50 is f5; a focal length ofthe sixth lens element 60 is f6; a focal length of the seventh lenselement 70 is f7; a focal length of the eighth lens element 80 is f8; arefractive index of the first lens element 10 is n1; a refractive indexof the second lens element 20 is n2; a refractive index of the thirdlens element 30 is n3; a refractive index of the fourth lens element 40is n4; a refractive index of the fifth lens element 50 is n5; arefractive index of the sixth lens element 60 is n6; a refractive indexof the seventh lens element 70 is n7; a refractive index of the eighthlens element 80 is n8; an Abbe number of the first lens element 10 isV1; an Abbe number of the second lens element 20 is V2; an Abbe numberof the third lens element 30 is V3; and an Abbe number of the fourthlens element 40 is V4; an Abbe number of the fifth lens element 50 isV5; an Abbe number of the sixth lens element 60 is V6; an Abbe number ofthe seventh lens element 70 is V7; and an Abbe number of the eighth lenselement 80 is V8.

In the present invention, D41t51 is defined as the distance from theobject-side surface 41 of the fourth lens element 40 to the object-sidesurface 51 of the fifth lens element 50 along the optical axis I, D41t61is defined as the distance from the object-side surface 41 of the fourthlens element 40 to the object-side surface 61 of the sixth lens element60 along the optical axis I, D11t41 is defined as the distance from theobject-side surface 11 of the first lens element 10 to the object-sidesurface 41 of the fourth lens element 40 along the optical axis I,D42t52 is defined as the distance from the image-side surface 42 of thefourth lens element 40 to the image-side surface 52 of the fifth lenselement 50 along the optical axis I, D62t82 is defined as the distancefrom the image-side surface 62 of the sixth lens element 60 to theimage-side surface 82 of the eighth lens element 80 along the opticalaxis I, D31t52 is defined as the distance from the object-side surface31 of the third lens element 30 to the image-side surface 52 of thefifth lens element 50 along the optical axis I, D41t62 is defined as thedistance from the object-side surface 41 of the fourth lens element 40to the image-side surface 62 of the sixth lens element 60 along theoptical axis I, D31t42 is defined as the distance from the object-sidesurface 31 of the third lens element 30 to the image-side surface 42 ofthe fourth lens element 40 along the optical axis I.

First Embodiment

Please refer to FIG. 6 which illustrates the first embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG. 7Afor the longitudinal spherical aberration on the image plane 4 of thefirst embodiment; please refer to FIG. 7B for the field curvatureaberration on the sagittal direction; please refer to FIG. 7C for thefield curvature aberration on the tangential direction; and please referto FIG. 7D for the distortion aberration. The Y axis of the sphericalaberration in each embodiment is “field of view” for 1.0. The Y axis ofthe astigmatic field and the distortion in each embodiment stands for“image height” (ImgH), which is 5.467 mm.

Only the eight lens elements 10, 20, 30, 40, 50, 60, 70 and 80 of theoptical imaging lens 1 of the first embodiment have refracting power.The optical imaging lens 1 also has an aperture stop 2, a filter 3, andan image plane 4. The aperture stop 2 is disposed on the side of thefirst lens element 10 facing the object side A1.

The first lens element 10 has positive refracting power. An optical axisregion 13 of the object-side surface 11 of the first lens element 10 isconvex, and a periphery region 14 of the object-side surface 11 of thefirst lens element 10 is convex. An optical axis region 16 of theimage-side surface 12 of the first lens element 10 is concave, and aperiphery region 17 of the image-side surface 12 of the first lenselement 10 is concave. Besides, both the object-side surface 11 and theimage-side surface 12 of the first lens element 10 are asphericsurfaces, but it is not limited thereto.

The second lens element 20 has negative refracting power. An opticalaxis region 23 of the object-side surface 21 of the second lens element20 is convex, and a periphery region 24 of the object-side surface 21 ofthe second lens element 20 is convex. An optical axis region 26 of theimage-side surface 22 of the second lens element 20 is concave, and aperiphery region 27 of the image-side surface 22 of the second lenselement 20 is concave. Besides, both the object-side surface 21 and theimage-side surface 22 of the second lens element 20 are asphericsurfaces, but it is not limited thereto.

The third lens element 30 has negative refracting power. An optical axisregion 33 of the object-side surface 31 of the third lens element 30 isconcave, and a periphery region 34 of the object-side surface 31 of thethird lens element 30 is concave. An optical axis region 36 of theimage-side surface 32 of the third lens element 30 is concave, and aperiphery region 37 of the image-side surface 32 of the third lenselement 30 is convex. Besides, both the object-side surface 31 and theimage-side surface 32 of the third lens element 30 are asphericsurfaces, but it is not limited thereto.

The fourth lens element 40 has positive refracting power. An opticalaxis region 43 of the object-side surface 41 of the fourth lens element40 is concave, and a periphery region 44 of the object-side surface 41of the fourth lens element 40 is concave. An optical axis region 46 ofthe image-side surface 42 of the fourth lens element 40 is convex, and aperiphery region 47 of the image-side surface 42 of the fourth lenselement 40 is convex. Besides, both the object-side surface 41 and theimage-side surface 42 of the fourth lens element 40 are asphericsurfaces, but it is not limited thereto.

The fifth lens element 50 has positive refracting power. An optical axisregion 53 of the object-side surface 51 of the fifth lens element 50 isconvex, and a periphery region 54 of the object-side surface 51 of thefifth lens element 50 is concave. An optical axis region 56 of theimage-side surface 52 of the fifth lens element 50 is concave, and aperiphery region 57 of the image-side surface 52 of the fifth lenselement 50 is convex. Besides, both the object-side surface 51 and theimage-side surface 52 of the fifth lens element 50 are asphericsurfaces, but it is not limited thereto.

The sixth lens element 60 has negative refracting power. An optical axisregion 63 of the object-side surface 61 of the sixth lens element 60 isconcave, and a periphery region 64 of the object-side surface 61 of thesixth lens element 60 is concave. An optical axis region 66 of theimage-side surface 62 of the sixth lens element 60 is convex, and aperiphery region 67 of the image-side surface 62 of the sixth lenselement 60 is convex. Besides, both the object-side surface 61 and theimage-side surface 62 of the sixth lens element 60 are asphericsurfaces, but it is not limited thereto.

The seventh lens element 70 has negative refracting power. An opticalaxis region 73 of the object-side surface 71 of the seventh lens element70 is convex, and a periphery region 74 of the object-side surface 71 ofthe seventh lens element 70 is concave. An optical axis region 76 of theimage-side surface 72 of the seventh lens element 70 is concave, and aperiphery region 77 of the image-side surface 72 of the seventh lenselement 70 is convex. Besides, both the object-side surface 71 and theimage-side surface 72 of the seventh lens element 70 are asphericsurfaces, but it is not limited thereto.

The eighth lens element 80 has negative refracting power. An opticalaxis region 83 of the object-side surface 81 of the eighth lens element80 is convex, and a periphery region 84 of the object-side surface 81 ofthe eighth lens element 80 is convex. An optical axis region 86 of theimage-side surface 82 of the eighth lens element 80 is concave, and aperiphery region 87 of the image-side surface 82 of the eighth lenselement 80 is convex. Besides, both the object-side surface 81 and theimage-side surface 82 of the eighth lens element 80 are asphericsurfaces, but it is not limited thereto.

In the first lens element 10, the second lens element 20, the third lenselement 30, the fourth lens element 40, the fifth lens element 50, thesixth lens element 60, the seventh lens element 70 and the eighth lenselement 80 of the optical imaging lens element 1 of the presentinvention, there are 16 surfaces, such as the object-side surfaces11/21/31/41/51/61/71/81 and the image-side surfaces12/22/32/42/52/62/72/82. If a surface is aspheric, these asphericcoefficients are defined according to the following formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}{a_{i} \times Y^{i}}}}$

In which:

Y represents a vertical distance from a point on the aspheric surface tothe optical axis;

Z represents the depth of an aspheric surface (the perpendiculardistance between the point of the aspheric surface at a distance Y fromthe optical axis and the tangent plane of the vertex on the optical axisof the aspheric surface);

R represents the curvature radius of the lens element surface;

K is a conic constant; and

a_(i) is the aspheric coefficient of the i^(th) order, in which the a₂coefficient of each embodiment is 0.

The optical data of the first embodiment of the optical imaging lens 1are shown in FIG. 22 while the aspheric surface data are shown in FIG.23 . In the present embodiments of the optical imaging lens, thef-number of the entire optical imaging lens element system is Fno, EFLis the effective focal length, HFOV stands for the half field of viewwhich is half of the field of view of the entire optical imaging lenselement system, and the unit for the curvature radius, the thickness andthe focal length is in millimeters (mm). In this embodiment, EFL=7.711mm; HFOV=40.842 degrees; TTL=9.798 mm; Fno=1.702; ImgH=5.467 mm.

Second Embodiment

Please refer to FIG. 8 which illustrates the second embodiment of theoptical imaging lens 1 of the present invention. It is noted that fromthe second embodiment to the following embodiments, in order to simplifythe figures, only the components different from what the firstembodiment has, and the basic lens elements will be labeled in figures.Other components that are the same as what the first embodiment has,such as the object-side surface, the image-side surface, the portion ina vicinity of the optical axis and the portion in a vicinity of itsperiphery will be omitted in the following embodiments. Please refer toFIG. 9A for the longitudinal spherical aberration on the image plane 4of the second embodiment, please refer to FIG. 9B for the fieldcurvature aberration on the sagittal direction, please refer to FIG. 9Cfor the field curvature aberration on the tangential direction, andplease refer to FIG. 9D for the distortion aberration. The components inthis embodiment are similar to those in the first embodiment, but theoptical data such as the lens element refracting power, the radius ofcurvature, the lens element thickness, the aspheric surface or the backfocal length in this embodiment are different from the optical data inthe first embodiment. Besides, in this embodiment, the optical axisregion 33 of the object-side surface 31 of the third lens element 30 isconvex, the optical axis region 43 of the object-side surface 41 of thefourth lens element 40 is convex, the fifth lens element 50 has negativerefracting power, the sixth lens element 60 has positive refractingpower, the optical axis region 63 of the object-side surface 61 of thesixth lens element 60 is convex, the periphery region 84 of theobject-side surface 81 of the eighth lens element 80 is concave.

The optical data of the second embodiment of the optical imaging lensare shown in FIG. 22 while the aspheric surface data are shown in FIG.23 . In this embodiment, EFL=8.398 mm; HFOV=40.842 degrees; TTL=10.014mm; Fno=1.854; ImgH=5.849 mm. In particular: 1. The thickness differencebetween the optical axis region and the periphery region of the lenselement of this embodiment is smaller than that of the first embodiment,and it is easy to manufacture, so the yield is high.

Third Embodiment

Please refer to FIG. 10 which illustrates the third embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.11A for the longitudinal spherical aberration on the image plane 4 ofthe third embodiment; please refer to FIG. 11B for the field curvatureaberration on the sagittal direction; please refer to FIG. 11C for thefield curvature aberration on the tangential direction; and please referto FIG. 11D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the lens element refracting power, the radius of curvature,the lens element thickness, the aspheric surface or the back focallength in this embodiment are different from the optical data in thefirst embodiment.

The optical data of the third embodiment of the optical imaging lens areshown in FIG. 24 while the aspheric surface data are shown in FIG. 25 .In this embodiment, EFL=8.647 mm; HFOV=40.842 degrees; TTL=9.384 mm;Fno=1.909; ImgH=5.742 mm. In particular: 1. The system length of theoptical imaging lens TTL in this embodiment is shorter than the systemlength of the optical imaging lens TTL in the first embodiment; 2. Thedistortion aberration in this embodiment is better than the distortionaberration in the first embodiment.

Fourth Embodiment

Please refer to FIG. 12 which illustrates the fourth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.13A for the longitudinal spherical aberration on the image plane 4 ofthe fourth embodiment; please refer to FIG. 13B for the field curvatureaberration on the sagittal direction; please refer to FIG. 13C for thefield curvature aberration on the tangential direction; and please referto FIG. 13D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the lens element refracting power, the radius of curvature,the lens element thickness, the aspheric surface or the back focallength in this embodiment are different from the optical data in thefirst embodiment. Besides, in this embodiment, the optical axis region33 of the object-side surface 31 of the third lens element 30 is convex,the fifth lens element 50 has negative refracting power, the sixth lenselement 60 has positive refracting power, the optical axis region 63 ofthe object-side surface 61 of the sixth lens element 60 is convex, theseventh lens element 70 has positive refracting power, the peripheryregion 84 of the object-side surface 81 of the eighth lens element 80 isconcave.

The optical data of the fourth embodiment of the optical imaging lensare shown in FIG. 26 while the aspheric surface data are shown in FIG.27 . In this embodiment, EFL=7.681 mm; HFOV=40.842 degrees; TTL=9.418mm; Fno=1.696; ImgH=6.033 mm. In particular: 1. The system length of theoptical imaging lens TTL in this embodiment is shorter than the systemlength of the optical imaging lens TTL in the first embodiment; 2. Thelongitudinal spherical aberration in this embodiment is smaller than thelongitudinal spherical aberration in the first embodiment; 3. The fieldcurvature aberration on the sagittal direction in this embodiment issmaller than the field curvature aberration on the sagittal direction inthe first embodiment; 4. The field curvature aberration on thetangential direction in this embodiment is smaller than the fieldcurvature aberration on the tangential direction in the firstembodiment; 5. The distortion aberration in this embodiment is betterthan the distortion aberration in the first embodiment.

Fifth Embodiment

Please refer to FIG. 14 which illustrates the fifth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.15A for the longitudinal spherical aberration on the image plane 4 ofthe fifth embodiment; please refer to FIG. 15B for the field curvatureaberration on the sagittal direction; please refer to FIG. 15C for thefield curvature aberration on the tangential direction, and please referto FIG. 15D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the lens element refracting power, the radius of curvature,the lens element thickness, the aspheric surface or the back focallength in this embodiment are different from the optical data in thefirst embodiment. Besides, in this embodiment, the optical axis region33 of the object-side surface 31 of the third lens element 30 is convex,the optical axis region 43 of the object-side surface 41 of the fourthlens element 40 is convex, the fifth lens element 50 has negativerefracting power, the sixth lens element 60 has positive refractingpower, the optical axis region 63 of the object-side surface 61 of thesixth lens element 60 is convex, the optical axis region 73 of theobject-side surface 71 of the seventh lens element 70 is concave, theeighth lens element 80 has positive refracting power, the peripheryregion 84 of the object-side surface 81 of the eighth lens element 80 isconcave.

The optical data of the fifth embodiment of the optical imaging lens areshown in FIG. 28 while the aspheric surface data are shown in FIG. 29 .In this embodiment, EFL=7.558 mm; HFOV=40.842 degrees; TTL=9.454 mm;Fno=1.669; ImgH=6.118 mm. In particular: 1. The system length of theoptical imaging lens TTL in this embodiment is shorter than the systemlength of the optical imaging lens TTL in the first embodiment; 2. Thelongitudinal spherical aberration in this embodiment is smaller than thelongitudinal spherical aberration in the first embodiment; 3. The fieldcurvature aberration on the sagittal direction in this embodiment issmaller than the field curvature aberration on the sagittal direction inthe first embodiment; 4. The field curvature aberration on thetangential direction in this embodiment is smaller than the fieldcurvature aberration on the tangential direction in the firstembodiment; 5. The distortion aberration in this embodiment is betterthan the distortion aberration in the first embodiment.

Sixth Embodiment

Please refer to FIG. 16 which illustrates the sixth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.17A for the longitudinal spherical aberration on the image plane 4 ofthe sixth embodiment; please refer to FIG. 17B for the field curvatureaberration on the sagittal direction; please refer to FIG. 17C for thefield curvature aberration on the tangential direction, and please referto FIG. 17D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the lens element refracting power, the radius of curvature,the lens element thickness, the aspheric surface or the back focallength in this embodiment are different from the optical data in thefirst embodiment. Besides, in this embodiment, the second lens element20 has positive refracting power, the optical axis region 33 of theobject-side surface 31 of the third lens element 30 is convex, theoptical axis region 43 of the object-side surface 41 of the fourth lenselement 40 is convex, the fifth lens element 50 has negative refractingpower, the sixth lens element 60 has positive refracting power, theoptical axis region 63 of the object-side surface 61 of the sixth lenselement 60 is convex, the optical axis region 73 of the object-sidesurface 71 of the seventh lens element 70 is concave.

The optical data of the sixth embodiment of the optical imaging lens areshown in FIG. 30 while the aspheric surface data are shown in FIG. 31 .In this embodiment, EFL=7.134 mm; HFOV=40.842 degrees; TTL=9.183 mm;Fno=1.575; ImgH=5.937 mm. In particular: 1. The system length of theoptical imaging lens TTL in this embodiment is shorter than the systemlength of the optical imaging lens TTL in the first embodiment; 2. Thelongitudinal spherical aberration in this embodiment is smaller than thelongitudinal spherical aberration in the first embodiment; 3. The fieldcurvature aberration on the sagittal direction in this embodiment issmaller than the field curvature aberration on the sagittal direction inthe first embodiment; 4. The field curvature aberration on thetangential direction in this embodiment is smaller than the fieldcurvature aberration on the tangential direction in the firstembodiment; 5. The distortion aberration in this embodiment is betterthan the distortion aberration in the first embodiment.

Seventh Embodiment

Please refer to FIG. 18 which illustrates the seventh embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.19A for the longitudinal spherical aberration on the image plane 4 ofthe seventh embodiment; please refer to FIG. 19B for the field curvatureaberration on the sagittal direction; please refer to FIG. 19C for thefield curvature aberration on the tangential direction, and please referto FIG. 19D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the lens element refracting power, the radius of curvature,the lens element thickness, the aspheric surface or the back focallength in this embodiment are different from the optical data in thefirst embodiment. Besides, in this embodiment, the third lens element 30has positive refracting power, the optical axis region 33 of theobject-side surface 31 of the third lens element 30 is convex, theperiphery region 37 of the image-side surface 32 of the third lenselement 30 is concave, the fourth lens element 40 has negativerefracting power, the fifth lens element 50 has negative refractingpower, the sixth lens element 60 has positive refracting power, theoptical axis region 63 of the object-side surface 61 of the sixth lenselement 60 is convex, the periphery region 84 of the object-side surface81 of the eighth lens element 80 is concave.

The optical data of the seventh embodiment of the optical imaging lensare shown in FIG. 32 while the aspheric surface data are shown in FIG.33 . In this embodiment, EFL=7.033 mm; HFOV=40.842 degrees; TTL=9.103mm; Fno=1.553; ImgH=6.049 mm. In particular: 1. The system length of theoptical imaging lens TTL in this embodiment is shorter than the systemlength of the optical imaging lens TTL in the first embodiment; 2. Thelongitudinal spherical aberration in this embodiment is smaller than thelongitudinal spherical aberration in the first embodiment; 3. Thedistortion aberration in this embodiment is better than the distortionaberration in the first embodiment.

Some important ratios in each embodiment are shown in FIG. 34 and FIG.35 .

Each embodiment of the present invention provides an optical imaginglens which has good imaging quality. For example, the following lenselement concave or convex configuration may effectively reduce the fieldcurvature aberration and the distortion aberration to optimize theimaging quality of the optical imaging lens. Furthermore, the presentinvention has the corresponding advantages:

1. The optical imaging lens 1 of the present invention satisfies therelationships that the optical axis region 66 of the image-side surface62 of the sixth lens element 60 is convex, the optical axis region 83 ofthe object-side surface 81 of the eighth lens element 80 is convex, andthe periphery region 87 of the image-side surface 82 of the eighth lenselement 80 is convex, and the optical imaging lens 1 satisfies therelationship of D41t51/(T3+G34)≥1.700, which is beneficial to the designan optical imaging lens with large aperture and large image height. Ifthe optical imaging lens 1 further satisfies the followingrelationships: the first lens element 10 has positive refracting power,the periphery region 17 of the image-side surface 12 of the first lenselement 10 is concave, and the periphery region 34 of the object-sidesurface 31 of the third lens element 30 is concave, it is beneficial tocorrect the aberration of the inner field of view (0.2˜0.4 Field), andthe preferable range is 1.700≤D41t51/(T3+G34)≤6.000.

2. The optical imaging lens 1 of the present invention satisfies therelationships that the optical axis region 66 of the image-side surface62 of the sixth lens element 60 is convex, the optical axis region 83 ofthe object-side surface 81 of the eighth lens element 80 is convex, theperiphery region 87 of the image-side surface 82 of the eighth lenselement 80 is convex, and D41t51/(T3+G34)≥1.700, which is beneficial tothe design an optical imaging lens with large aperture and large imageheight. If the optical imaging lens 1 further satisfies the followingrelationships: the periphery region 34 of the object-side surface 31 ofthe third lens element 30 is concave and the periphery region 44 of theobject-side surface 41 of the fourth lens element 40 is concave, it isbeneficial to correct the aberration of the inner field of view (0.2˜0.4Field), and the preferable range is 1.700≤D41t51/(T3+G34)≤6.000. Theoptical imaging lens 1 further restricts that the first lens element 10has positive refracting power, which is beneficial to shorten the systemlength.

3. The optical imaging lens 1 of the present invention satisfies therelationships that the optical axis region 66 of the image-side surface62 of the sixth lens element 60 is convex, the optical axis region 83 ofthe object-side surface 81 of the eighth lens element 80 is convex, theperiphery region 87 of the image-side surface 82 of the eighth lenselement 80 is convex, and D41t61/(T3+G34)≥3.700, which is beneficial tothe design an optical imaging lens with large aperture and large imageheight. If the optical imaging lens further satisfies the followingrelationships: the first lens element 10 has positive refracting power,the periphery region 17 of the image-side surface 12 of the first lenselement 10 is concave, the second lens 20 has negative refracting powerand the periphery region 47 of the image-side surface 42 of the fourthlens element 40 is convex, it is beneficial to correct the aberration ofthe inner field of view (0.2˜0.4 Field), and the preferable range is3.700≤D41t61/(T3+G34)≤8.000.

4. The optical imaging lens of the invention satisfies the relationshipsof V3+V8≤100.000, V7+V8≤100.000 or 55.000≤V2+V6, which is beneficial toimprove the MTF (modulation transfer function), thereby increasing theresolution of the optical imaging lens, and the preferable range are38.0005V3+V8100.000, 38.000≤V7+V8≤100.000, or 55.000V2+V6≤1206000.

5. When the optical imaging lens of the present invention furthersatisfies the relationships listed in Table 1 below, it is helpful tokeep the thickness and gaps of each lens element at an appropriate valueon the premise of providing an optical imaging lens with large apertureand large image height, so as to avoid that any parameter is too largeto be beneficial to the overall thinness of the optical imaging lens, orthat any parameter is too small to affect the assembly or improve themanufacturing difficulty.

TABLE 1 Relationships Preferable range D11t41/T4 ≤ 4.300 1.300 ≤D11t41/T4 ≤ 4.300 (D42t52 + D62t82)/(G56 + T6) ≤ 4.100 1.000 ≤ (D42t52 +D62t82)/(G56 + T6) ≤ 4.100 EFL/(T1 + T6 + T8) ≤ 4.000 2.200 ≤ EFL/(T1 +T6 + T8) ≤ 4.000 TTL/(T1 + G56 + T6 + T8) ≤ 4.000 2.200 ≤ TTL/(T1 +G56 + T6 + T8) ≤ 4.000 Fno*(T1 + G12 + T3 + G34)/(T2 + G23) ≤ 3.1102.100 ≤ Fno*(T1 + G12 + T3 + G34)/(T2 + G23) ≤ 3.110 3.800 ≤ (ImgH +EPD + G56 + T6)/D31t52 3.800 ≤ (ImgH + EPD + G56 + T6)/D31t52 ≤ 6.000Fno*(T2 + G34 + T4 + D62t82)/AAG ≤ 3.600 0.900 ≤ Fno*(T2 + G34 + T4 +D62t82)/AAG ≤ 3.600 6.100 ≤ (ImgH + D41t62)/(G67 + T7 + G78) 6.100 ≤(ImgH + D41t62)/(G67 + T7 + G78) ≤ 12.000 Fno*(ALT + BFL)/D41t62 ≤ 4.0002.100 ≤ Fno*(ALT + BFL)/D41t62 ≤ 4.000 3.600 ≤ EPD/(G67 + T7) 3.600 ≤EPD/(G67 + T7) ≤ 21.000 Fno*TTL/EPD ≤ 4.100 2.400 ≤ Fno*TTL/EPD ≤ 4.100D31t42/T8 ≤ 2.700 1.600 ≤ D31t42/T8 ≤ 2.700 (D11t41 + D41t62)/D62t82 ≤5.400 2.300 ≤ (D11t41 + D41t62)/D62t82 ≤ 5.400 3.000 ≤ (EPD +EFL)/D11t41 3.000 ≤ (EPD + EFL)/D11t41 ≤ 5.500

By observing three representative wavelengths of rays in each embodimentof the present invention, it is suggested off-axis ray of differentheights of every wavelength all concentrates on the image plane, anddeviations of every curve also reveal that off-axis ray of differentheights are well controlled so the embodiments do improve the sphericalaberration, the astigmatic aberration and the distortion aberration. Inaddition, by observing the imaging quality data the distances amongstthe three representing different wavelengths of rays are pretty close toone another, which means the embodiments of the present invention areable to concentrate ray of the three representing different wavelengthsso that the aberration is greatly improved. Given the above, it isunderstood that the embodiments of the present invention providesoutstanding imaging quality.

In addition, any arbitrary combination of the parameters of theembodiments can be selected to increase the lens limitation so as tofacilitate the design of the same structure of the present invention.

In the ray of the unpredictability of the optical imaging lens, thepresent invention suggests the above principles to have a larger fieldof view, a shorter system length of the optical imaging lens, betterimaging quality or a better fabrication yield to overcome the drawbacksof prior art. And by use of plastic material for the lens element of thepresent invention can further reduce the weight and cost of the opticalimaging lens.

In addition to the above ratios, one or more conditional formulae may beoptionally combined to be used in the embodiments of the presentinvention and the present invention is not limit to this. The concave orconvex configuration of each lens element or multiple lens elements maybe fine-tuned to enhance the performance and/or the resolution. Theabove limitations may be selectively combined in the embodiments withoutcausing inconsistency.

The contents in the embodiments of the invention include but are notlimited to a focal length, a thickness of a lens element, an Abbenumber, or other optical parameters. For example, in the embodiments ofthe invention, an optical parameter A and an optical parameter B aredisclosed, wherein the ranges of the optical parameters, comparativerelation between the optical parameters, and the range of a conditionalexpression covered by a plurality of embodiments are specificallyexplained as follows:

(1) The ranges of the optical parameters are, for example, α₂≤A≤α₁ orβ₂≤B≤β₁, where α₁ is a maximum value of the optical parameter A amongthe plurality of embodiments, α₂ is a minimum value of the opticalparameter A among the plurality of embodiments, β₁ is a maximum value ofthe optical parameter B among the plurality of embodiments, and β₂ is aminimum value of the optical parameter B among the plurality ofembodiments.

(2) The comparative relation between the optical parameters is that A isgreater than B or A is less than B, for example.

(3) The range of a conditional expression covered by a plurality ofembodiments is in detail a combination relation or proportional relationobtained by a possible operation of a plurality of optical parameters ineach same embodiment. The relation is defined as E, and E is, forexample, A+B or A−B or A/B or A*B or (A*B)^(1/2), and E satisfies aconditional expression E≤γ₁ or E≥γ₂ or γ₂≤E≤γ₁, where each of γ₁ and γ₂is a value obtained by an operation of the optical parameter A and theoptical parameter B in a same embodiment, γ₁ is a maximum value amongthe plurality of the embodiments, and γ₂ is a minimum value among theplurality of the embodiments.

The ranges of the aforementioned optical parameters, the aforementionedcomparative relations between the optical parameters, and a maximumvalue, a minimum value, and the numerical range between the maximumvalue and the minimum value of the aforementioned conditionalexpressions are all implementable and all belong to the scope disclosedby the invention. The aforementioned description is for exemplaryexplanation, but the invention is not limited thereto.

The embodiments of the invention are all implementable. In addition, acombination of partial features in a same embodiment can be selected,and the combination of partial features can achieve the unexpectedresult of the invention with respect to the prior art. The combinationof partial features includes but is not limited to the surface shape ofa lens element, a refracting power, a conditional expression or thelike, or a combination thereof. The description of the embodiments isfor explaining the specific embodiments of the principles of theinvention, but the invention is not limited thereto. Specifically, theembodiments and the drawings are for exemplifying, but the invention isnot limited thereto.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. An optical imaging lens, from an object side toan image side in order along an optical axis comprising: a first lenselement, a second lens element, a third lens element, a fourth lenselement, a fifth lens element, a sixth lens element, a seventh lenselement and an eighth lens element, the first lens element to the eighthlens element each having an object-side surface facing toward the objectside and allowing imaging rays to pass through as well as an image-sidesurface facing toward the image side and allowing the imaging rays topass through, wherein: the first lens element has positive refractingpower, and a periphery region of the image-side surface of the firstlens element is concave; a periphery region of the object-side surfaceof the third lens element is concave; an optical axis region of theimage-side surface of the sixth lens element is convex; an optical axisregion of the object-side surface of the eighth lens element is convex,and a periphery region of the image-side surface of the eighth lenselement is convex; wherein lens elements included by the optical imaginglens are only the eight lens elements described above, and wherein theoptical imaging lens satisfies the relationships: D41t51/(T3+G34)≥1.700,wherein D41t51 is defined as the distance from the object-side surfaceof the fourth lens element to the object-side surface of the fifth lenselement along the optical axis, T3 is a thickness of the third lenselement along the optical axis, G34 is an air gap between the third lenselement and the fourth lens element along the optical axis.
 2. Theoptical imaging lens of claim 1, wherein D11t41 is defined as thedistance from the object-side surface of the first lens element to theobject-side surface of the fourth lens element along the optical axis,T4 is a thickness of the fourth lens element along the optical axis, andthe optical imaging lens satisfies the relationship: D11t41/T4≤4.300. 3.The optical imaging lens of claim 1, wherein T6 is a thickness of thesixth lens element along the optical axis, G56 is an air gap between thefifth lens element and the sixth lens element along the optical axis,D42t52 is defined as the distance from the image-side surface of thefourth lens element to the image-side surface of the fifth lens elementalong the optical axis, D62t82 is defined as the distance from theimage-side surface of the sixth lens element to the image-side surfaceof the eighth lens element along the optical axis, and the opticalimaging lens satisfies the relationship: (D42t52+D62t82)/(G56+T6)≤4.100.4. The optical imaging lens of claim 1, wherein EFL is an effectivefocal length of the optical imaging lens, T1 is a thickness of the firstlens element along the optical axis, T6 is a thickness of the sixth lenselement along the optical axis, T8 is a thickness of the eighth lenselement along the optical axis, and the optical imaging lens satisfiesthe relationship: EFL/(T1+T6+T8)≤4.000.
 5. The optical imaging lens ofclaim 1, wherein TTL is the distance from the object-side surface of thefirst lens element to an image plane along the optical axis, T1 is athickness of the first lens element along the optical axis, T6 is athickness of the sixth lens element along the optical axis, T8 is athickness of the eighth lens element along the optical axis, G56 is anair gap between the fifth lens element and the sixth lens element alongthe optical axis, and the optical imaging lens satisfies therelationship: TTL/(T1+G56+T6+T8)≤4.000.
 6. The optical imaging lens ofclaim 1, wherein Fno is a f-number of the optical imaging lens, T1 is athickness of the first lens element along the optical axis, T2 is athickness of the second lens element along the optical axis, G12 is anair gap between the first lens element and the second lens element alongthe optical axis, G23 is an air gap between the second lens element andthe third lens element along the optical axis, and the optical imaginglens satisfies the relationship: Fno*(T1+G12+T3+G34)/(T2+G23)≤3.110. 7.The optical imaging lens of claim 1, wherein ImgH is an image height ofthe optical imaging lens, EPD is an entrance pupil diameter of theoptical imaging lens, T6 is a thickness of the sixth lens element alongthe optical axis, G56 is an air gap between the fifth lens element andthe sixth lens element along the optical axis, D31t52 is defined as thedistance from the object-side surface of the third lens element to theimage-side surface of the fifth lens element along the optical axis, andthe optical imaging lens satisfies the relationship:3.800≤(ImgH+EPD+G56+T6)/D31t52.
 8. An optical imaging lens, from anobject side to an image side in order along an optical axis comprising:a first lens element, a second lens element, a third lens element, afourth lens element, a fifth lens element, a sixth lens element, aseventh lens element and an eighth lens element, the first lens elementto the eighth lens element each having an object-side surface facingtoward the object side and allowing imaging rays to pass through as wellas an image-side surface facing toward the image side and allowing theimaging rays to pass through, wherein: a periphery region of theobject-side surface of the third lens element is concave; a peripheryregion of the object-side surface of the fourth lens element is concave;an optical axis region of the image-side surface of the sixth lenselement is convex; an optical axis region of the object-side surface ofthe eighth lens element is convex, and a periphery region of theimage-side surface of the eighth lens element is convex; wherein lenselements included by the optical imaging lens are only the eight lenselements described above, and wherein the optical imaging lens satisfiesthe relationships: D41t51/(T3+G34)≥1.700, wherein D41t51 is defined asthe distance from the object-side surface of the fourth lens element tothe object-side surface of the fifth lens element along the opticalaxis, T3 is a thickness of the third lens element along the opticalaxis, G34 is an air gap between the third lens element and the fourthlens element along the optical axis.
 9. The optical imaging lens ofclaim 8, wherein V3 is an Abbe number of the third lens element, V8 isan Abbe number of the eighth lens element, and the optical imaging lenssatisfies the relationship: V3+V8≤100.000.
 10. The optical imaging lensof claim 8, wherein V7 is an Abbe number of the seventh lens element, V8is an Abbe number of the eighth lens element, and the optical imaginglens satisfies the relationship: V7+V8≤100.000.
 11. The optical imaginglens of claim 8, wherein Fno is a f-number of the optical imaging lens,T2 is a thickness of the second lens element along the optical axis, T4is a thickness of the fourth lens element along the optical axis, D62t82is defined as the distance from the image-side surface of the sixth lenselement to the image-side surface of the eighth lens element along theoptical axis, AAG is a sum of seven air gaps from the first lens elementto the eighth lens element along the optical axis, and the opticalimaging lens satisfies the relationship:Fno*(T2+G34+T4+D62t82)/AAG≤3.600.
 12. The optical imaging lens of claim8, wherein ImgH is an image height of the optical imaging lens, D41t62is defined as the distance from the object-side surface of the fourthlens element to the image-side surface of the sixth lens element alongthe optical axis, T7 is a thickness of the seventh lens element alongthe optical axis, G67 is an air gap between the sixth lens element andthe seventh lens element along the optical axis, G78 is an air gapbetween the seventh lens element and the eighth lens element along theoptical axis, and the optical imaging lens satisfies the relationship:6.100≤(ImgH+D41t62)/(G67+T7+G78).
 13. The optical imaging lens of claim8, wherein Fno is a f-number of the optical imaging lens, ALT is a sumof thicknesses of the eight lens elements from the first lens element tothe eighth lens element along the optical axis, BFL is a distance fromthe image-side surface of the eighth lens element to an image planealong the optical axis, D41t62 is defined as the distance from theobject-side surface of the fourth lens element to the image-side surfaceof the sixth lens element along the optical axis, and the opticalimaging lens satisfies the relationship: Fno*(ALT+BFL)/D41t62≤4.000. 14.The optical imaging lens of claim 8, wherein EPD is an entrance pupildiameter of the optical imaging lens, T7 is a thickness of the seventhlens element along the optical axis, G67 is an air gap between the sixthlens element and the seventh lens element along the optical axis, andthe optical imaging lens satisfies the relationship: 3.600≤EPD/(G67+T7).15. An optical imaging lens, from an object side to an image side inorder along an optical axis comprising: a first lens element, a secondlens element, a third lens element, a fourth lens element, a fifth lenselement, a sixth lens element, a seventh lens element and an eighth lenselement, the first lens element to the eighth lens element each havingan object-side surface facing toward the object side and allowingimaging rays to pass through as well as an image-side surface facingtoward the image side and allowing the imaging rays to pass through,wherein: the first lens element has positive refracting power, and aperiphery region of the image-side surface of the first lens element isconcave; the second lens element has negative refracting power; aperiphery region of the image-side surface of the fourth lens element isconvex; an optical axis region of the image-side surface of the sixthlens element is convex; an optical axis region of the object-sidesurface of the eighth lens element is convex, and a periphery region ofthe image-side surface of the eighth lens element is convex; whereinlens elements included by the optical imaging lens are only the eightlens elements described above, and wherein the optical imaging lenssatisfies the relationships: D41t61/(T3+G34)≥3.700, wherein D41t61 isdefined as the distance from the object-side surface of the fourth lenselement to the object-side surface of the sixth lens element along theoptical axis, T3 is a thickness of the third lens element along theoptical axis, G34 is an air gap between the third lens element and thefourth lens element along the optical axis.
 16. The optical imaging lensof claim 15, wherein V2 is an Abbe number of the second lens element, V6is an Abbe number of the sixth lens element, and the optical imaginglens satisfies the relationship: 55.000≤V2+V6.
 17. The optical imaginglens of claim 15, wherein Fno is a f-number of the optical imaging lens,TTL is the distance from the object-side surface of the first lenselement to an image plane along the optical axis, EPD is an entrancepupil diameter of the optical imaging lens, and the optical imaging lenssatisfies the relationship: Fno*TTL/EPD≤4.100.
 18. The optical imaginglens of claim 15, wherein D31t42 is defined as the distance from theobject-side surface of the third lens element to the image-side surfaceof the fourth lens element along the optical axis, T8 is a thickness ofthe eighth lens element along the optical axis, and the optical imaginglens satisfies the relationship: D31t42/T8≤2.700.
 19. The opticalimaging lens of claim 15, wherein D11t41 is defined as the distance fromthe object-side surface of the first lens element to the object-sidesurface of the fourth lens element along the optical axis, D41t62 isdefined as the distance from the object-side surface of the fourth lenselement to the image-side surface of the sixth lens element along theoptical axis, D62t82 is defined as the distance from the image-sidesurface of the sixth lens element to the image-side surface of theeighth lens element along the optical axis, and the optical imaging lenssatisfies the relationship: (D11t41+D41t62)/D62t82≤5.400.
 20. Theoptical imaging lens of claim 15, wherein EPD is an entrance pupildiameter of the optical imaging lens, EFL is an effective focal lengthof the optical imaging lens, D11t41 is defined as the distance from theobject-side surface of the first lens element to the object-side surfaceof the fourth lens element along the optical axis, and the opticalimaging lens satisfies the relationship: 3.000≤(EPD+EFL)/D11t41.